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Flaw in creationist solution to the Pioneer anomaly?

Published: 11 May 2013 (GMT+10)

In 2008, Creationist physicist and cosmologist Dr Russ Humphreys published a solution to the Pioneer anomaly in Journal of Creation (see The ‘Pioneer anomaly’ for a general introduction). The Pioneer anomaly is a small but strange deceleration of four outgoing spacecraft: Galileo, Ulysses, and Pioneers 10 and 11. Dr Humphreys addresses some comments to a recent study that proposes a different solution.

NASA/Ames Research Center Pioneer 10
Pioneer 10

R.H. from the United States writes:

Question for Dr. Humphreys—Your cosmology suggests an original solution to the “pioneer anomaly”, but last year it was reported that it was solved without invoking a change in physics. It seems interesting to me that it took such a long time to solve something with such a seemingly obvious answer as the effects of heat. At any rate, I haven’t heard of any responses from creationists, which might imply that it’s agreed upon universally. But, I have to ask, is it a satisfactory answer, or is it still a useful argument for creation?

Dr Russ Humphreys responds:

Dear Mr. H.:

Thanks for your interest in this topic. Yes, I’ve been aware of the alleged answer to the Pioneer slowdown since it came out in Physical Review Letters last June (http://prl.aps.org/abstract/PRL/v108/i24/e241101). It is merely the latest in a long series of attempts to try to explain the anomaly with heat radiated excessively in the forward direction. The paper shows a graphic of hot and cold spots on the spacecraft from a computer simulation, but it offered no details on the simulation itself … yet it is crucial to the result they claim. The principal author, Slava Turyshev, e-mailed me on September 23 that his team was preparing a paper with the heat simulation details, but as of today Google Scholar can’t find it on the Internet, not even a preprint.

I’m suspicious of their result for several reasons:

  1. Back-of-envelope calculations I’ve done on the heat radiated make it seem unlikely. I’ve acquired a detailed report on the Pioneer physical structure, and I hope I can find enough details related to heat emission from various parts to do a better calculation.
  2. A graph of radar data in their paper shows the anomalous deceleration leveling out, not steadily declining (as they interpreted the graph). The value it levels out at is almost exactly the presently-observed/accepted value of the Hubble constant H times the speed of light c, even closer than in the earlier reports of the deceleration. To have “heat” accidentally give a number with such cosmic significance seems highly unlikely to me.
  3. Pioneers 10 and 11 were not the only spacecraft to show the anomaly. Galileo and Ulysses also showed about the same deceleration, but less clearly because they didn’t get as far from the Sun. Their structures were quite different from each other and from the Pioneers. How likely is it that they would accidentally radiate the right amounts of forward heat necessary to give decelerations also on the close order of Hc?

I’m waiting to see the alleged detailed thermal analysis from Turyshev et al. If it doesn’t materialize in a year or so, that will tell me they found a flaw in their analysis, and I’ll re-visit the issue in print. If it does materialize, I’ll go over it carefully and submit an update, possibly a letter, to Journal of Creation. In short, I think my explanation of the anomaly is still good (and some tweaks from my recent cosmology work may make it even better), but I can’t guarantee that yet.

Cordially in Christ,

Russ Humphreys

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